It all depends on what you mean by "low cost" and "profit"
Personally, I use Singlehop a lot, but it all depends on what you're doing. If all you're doing is just fliping the machine and tacking on an extra 10-40% you'll not get too far. It's all about what you bundle with the server after getting the machine.
There are dozens of low cost places out there that you can find for less than $80, but if you're looking to resell them, the same people looking for servers under $120 are looking for under $100 and will find those $80 servers.
Matching anyone on price alone is going to be a losing battle.